Many of the people reading this may already be taking a daily aspirin to prevent heart attacks and strokes because they heard it was good idea, but is it a good idea for everyone? Like many questions without simple answers, the answer to that question is "It depends".

It depends a lot on what an individuals particular risk is for the illnesses we are trying to prevent as well as their risk for developing the side effects that aspirin can cause. So what are the benefits of aspirin and what are the potential side effects? Aspirins is such a common drug that a whole mythology seems to have sprouted up about its life extending properties and for some it may be true but we need to look at science to separate the facts from the fairy tales.

The United States Preventive Services Task Force (USPSTF) is an independent government agency made up of experts in various fields of medicine. They periodically review all of the available scientific literature on a given subject and make recommendations based on the best available evidence. The last review was done in 2009 and they are currently working on an update to the recommendations which should be out sometime next year. Below is a summary of the existing recommendations.

The USPSTF recommends the use of aspirin for women age 55 to 79 years when the potential benefit of a reduction in ischemic strokes outweighs the potential harm of an increase in gastrointestinal hemorrhage. Go to the Clinical Considerations section for discussion of benefits and harms.

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of aspirin for cardiovascular disease prevention in men and women 80 years or older.

The USPSTF recommends against the use of aspirin for stroke prevention in women younger than 55 years and for myocardial infarction prevention in men younger than 45 years.

The USPSTF recommends the use of aspirin for men age 45 to 79 years when the potential benefit due to a reduction in myocardial infarctions outweighs the potential harm due to an increase in gastrointestinal hemorrhage. Go to the Clinical Considerations section for discussion of benefits and harms.

For people over 80 it seems that aspirin may not be a good idea because the risk of gastrointestinal bleeding becomes too high as we get older. For men under the age of 45 and women under 55 the risk of heart attack and stroke are too low to justify the use of aspirin. For people in between those age groups the decision is a little more complicated. In order to decide if you should take aspirin you need to calculate your cardiac risk and use the table below.

This table shows the risk level at which benefit ( heart attack and stroke prevention) exceeds harms ( gastrointestinal bleeding). To use the table, men should use the Coronary Heart Disease (CHD) calculator to determine their cardiac risk and women should use the Stroke Risk Calculator. To use these calculators you will need your blood pressure readings and cholesterol levels from your last exam.

Once you have your calculated risk you are ready to use the table. For example if a 62 year old man has a CHD risk of 10% then the benefits of aspirin outweigh the risks and he should consider taking a daily aspirin. The same could be said for a 58 year old woman who's stroke risk is 4%, while a 72 year old woman with a stroke risk of 10% probably should not take a daily aspirin.

A daily aspirin may keep the doctor away but it can also result in serious side effects that could land you in the hospital. Use this information only as a guide. Be sure to discuss the results with your physician before stopping or starting aspirin since medications you are taking may interact with your aspirin and other medical condition which you have may affect your risks of heart disease and bleeding.